Pressure-sensitive sensor

Abstract

The present invention aims at providing a pressure-sensitive sensor capable of layering a pressure-sensitive layer and electrodes with high productivity, facilitating control of contact between the pressure-sensitive layer and the electrodes by loading, achieving good reproducibility of a resistance value generated by loading between the pressure-sensitive ink layer and the electrodes, and measuring pressure with high accuracy. The pressure-sensitive sensor comprises a pair of electrodes 16 a and 16 b formed on a substrate film 31 , and a pressure-sensitive ink layer 30 juxtaposed to the electrodes on the substrate, the pressure-sensitive ink layer being variable in electrical properties in response to an applied pressing force, wherein a portion of the substrate film 31 having the pressure-sensitive ink layer 30 formed thereon is bent inward to allow the pressure-sensitive ink layer 30 to come into contact with the pair of electrodes 16 a and 16 b.

The invention claimed is: 
     
       1. A pressure-sensitive sensor comprising,
 a substrate having a rectangular portion and projecting portions which project from peripheries of the rectangular portion in the form of a trapezoid or a rectangle; 
 a pair of electrodes formed on the rectangular portion along the peripheries of the rectangular portion; and 
 a pressure-sensitive ink layer formed on the projecting portions, the pressure-sensitive ink layer being variable in electrical properties in response to an applied pressing force, 
 wherein the projecting portions are bent inward to allow the pressure-sensitive ink layer to come into contact with the pair of electrodes. 
 
     
     
       2. The pressure-sensitive sensor as claimed in  claim 1 , wherein each of the projecting portions has a root portion bent inward. 
     
     
       3. The pressure-sensitive sensor as claimed in  claim 2 , wherein the root portion has a half-cutout or bores in the form of broken line for facilitating inward bending of the root portion. 
     
     
       4. The pressure-sensitive sensor as claimed in  claim 2  or  3 , wherein the root portion is provided with cutouts at opposite ends thereof for preventing the portion of the substrate having the pressure-sensitive ink layer formed thereon from protruding outward when being bent inward. 
     
     
       5. The pressure-sensitive sensor as claimed in  claim 1 , wherein the pair of electrodes is formed in a loop along the peripheries of the rectangular portion. 
     
     
       6. The pressure-sensitive sensor as claimed in  claim 1 , wherein the projecting portions project from each of four sides of the rectangular portion in the form of a trapezoid. 
     
     
       7. The pressure-sensitive sensor as claimed in  claim 1 , wherein the projecting portions project from each of four corners of the rectangular portion.